وَإِنْ أَدْرَكَهُ فِي التَّشَهُّدِ، أَوْ فِي سُجُودِ السَّهْوِ: بَنَى عَلَيْهَا الْجُمُعَةَ عِنْدَ أَبِي حَنِيفَةَ وَأَبِي يُوسُفَ رَحِمَهُمَا اللَّهُ، وَقَالَ مُحَمَّدٌ: إِنْ أَدْرَكَ مَعَهُ أَكْثَرَ الرَّكْعَةِ الثَّانِيَةِ: بَنَى عَلَيْهَا الْجُمُعَةَ، وَإِنْ أَدْرَكَ مَعَهُ أَقَلَّهَا: بَنَى عَلَيْهَا الظُّهْرَ.
Translation: If the imam is joined during tashahhud or prostration of forgetfulness, Abu Hanifah and Abu Yusuf allow completing Jumuah; Muhammad requires catching most of the second rak‘ah, otherwise completing Zuhr.
Abu Hanifah and Abu Yusuf recognize joining the imam even in the final sitting; Muhammad requires reaching the major portion of the second rak‘ah. Their difference lies in the minimum participation that counts as catching Friday prayer.